High adhesion of a variety of rubber compounds to fabric using a single resorcinol-formaldehyde latex composition

ABSTRACT

A single adhesive composition for use in bonding more than one class of rubber polymer to textiles, in particular nylon and polyester fabric. The composition comprises an aqueous mixture of: a) about 85 to about 90 weight % polychloroprene latex; b) about 2 to about 6 weight % of at least one prepolymer of resorcinol with formaldehyde; c) about 4 to about 8% by weight of at least one blocked diisocyanate compound; and d) sufficient water to adjust the solids content of the mixture to about 15 to about 40% by weight; wherein the percentage of solids add-on on fabric treated with the composition ranges between about 5 and about 20% based on the weight of the untreated fabric. The preferred blocked diisocyanate compound is caprolactam blocked methylene-bis-(4-phenylisocyanate). The end-products that are contemplated for the present invention include, but are not limited to, diaphragms, molded articles, V-belt covers, conveyor belts, bead wraps for tires, hose wrap, dodge couplings and the like.

FIELD OF THE INVENTION

The present invention relates to an adhesive composition that is usedfor bonding a variety of rubber compounds to textiles. Morespecifically, the present invention relates to a single adhesivecomposition that bonds more than one class of elastomeric polymer tofabric to produce end-products such as diaphragms, molded articles,V-belt covers, conveyor belts, hose wrap and the like.

BACKGROUND OF THE INVENTION

For many products such as diaphragms, molded articles, bead wraps fortires, V-belt covers and the like, stringent requirements exist for thebond between the rubber and the substrate to which it is attached. It isonly by using special adhesives that sufficient adhesion is obtainedbetween rubber and synthetic fibers, since synthetic fibers have a lowaffinity for the rubber compound due to the lack of binding sites in thefibers.

Developed in 1935, the resorcinol-formaldehyde resins are among theoldest adhesives to achieve rubber to textile adhesion. They are used inan aqueous phase in conjunction with latex, hence they are commonlyreferred to as resorcinol-formaldehyde latex (RFL) compounds. Commonlyused RFL compounds are limited in several respects. First, some RFLs areable to bond to only one type of fabric. For example, a latex based onbutadiene-styrene-2-vinyl-pyridine ("vinylpyridine latex) was developedfor bonding rubber to polyamide fibers. This adhesive composition,however, is insufficient for bonding polyester fibers to rubber. Second,typical RFLs are formulated to bond only one class of elastomeric orrubber polymer to fabric. Consequently, to achieve strong adhesion of aparticular rubber to fabric using an RFL formulation, that particularrubber should be included in the RFL formulation. For example, to bindnitrile rubber to fabric, nitrile is typically used as a component inthe RFL formulation.

Because of the inability of existing RFL formulations to bind more thanone class of rubber polymer, it is necessary to prepare different RFLformulations during the fabric finishing process. The RFL formulationsthat are prepared will depend on the rubber compound that is to beultimately bound to the fabric. Such production of specifically tailoredadhesives is both time-consuming and costly. Changeovers with differentadhesive formulations are inefficient and time-consuming. Moreover,preparation of multiple adhesive formulations poses an increased risk inthe selection of the improper RFL formulation for treating the fabric.

While obtaining good adhesion between the desired rubber and treatedfabric is of paramount importance, there is a real need for thedevelopment of a single adhesive composition which can be used to bondmore than one class of elastomeric polymer to textiles.

SUMMARY OF THE INVENTION

The present invention is directed to a single adhesive composition foruse in bonding or reinforcing a variety of rubber polymers to textiles,in particular woven fabric. The composition comprises an aqueous mixtureof a) a polychloroprene latex; b) at least one prepolymer of resorcinolwith formaldehyde; c) at least one blocked diisocyanate compound, and d)sufficient water to adjust the solids content of the aqueous mixturefrom about 15 to about 40% by weight. The novelty of the presentinvention is based on the ability of the adhesive composition to bondmore than one class of rubber polymer to fabric.

The adhesive composition further includes additional formaldehyde whichenhances the chemical reaction of the aqueous mixture. A non-ionicsurfactant is also contained in the composition, and functions to lowerthe surface tension of the aqueous mixture. Sufficient alkaline such ascaustic soda is included as a catalyst and also to adjust the pH of thefinal composition between about 9 and about 11. If desired, carbon blackmay be added to the aqueous mixture to provide color.

The adhesive composition of the present invention overcomes thedisadvantages of current adhesive formulations by being compatible witha variety of natural and synthetic rubber polymers. Regardless of therubber that is bound to the fabric, a single adhesive composition hasbeen discovered which is capable of providing strong adhesion between avariety of rubbers and fabric substrates including, but not limited tonylon, polyester, and blends thereof.

For purposes of this invention, the elastomers or rubber polymersinclude, but are not limited to, polychloroprene, more commonly known asneoprene, nitrile, natural rubber, fluoroelastomer, hypalon, and EPDM(ethylene-propylene terpolymer). The end-products that are contemplatedby the present invention include, but are not limited to, diaphragms,molded articles, V-belt covers, conveyor belts, hose wrap, bead wrapsfor tires, dodge couplings and the like.

In one embodiment of the present invention, the adhesive composition forbonding a variety of rubber compounds to fabric, comprises an aqueousmixture of: a) about 85 to about 90 weight % polychloroprene latex; b)about 2 to about 6 weight % of at least one prepolymer of resorcinolwith formaldehyde; c) about 4 to about 8 weight % of at least oneblocked diisocyanate compound; and d) sufficient water to adjust thesolids content of the mixture to about 15 to about 40 weight %, whereinthe percentage of solids add-on on fabric treated with the adhesivecomposition ranges between about 5 and about 20% based on the untreatedfabric weight.

In yet one preferred embodiment, the blocked diisocyanate compound iscaprolactam blocked methylene-bis-(4-phenylisocyanate).

In another embodiment, the non-ionic surfactant is present in an amountof approximately 0.5 weight %.

A process is disclosed for adhering rubber compounds to syntheticfabric, comprising the steps of:

a) impregnating or dipping fabric in an aqueous mixture comprising apolychloroprene latex, a resorcinol-formaldehyde reaction product, atleast one blocked diisocyanate compound, and sufficient water to adjustthe solids content of the mixture to about 15 to about 40% by weight,wherein the percentage of solids add-on on fabric treated with themixture ranges between about 5 and about 20% based on the weight of theuntreated fabric;

b) drying the treated fabric at temperatures ranging between about 220°and 270° F. for approximately 1 minute;

c) curing the dried fabric for about 2 minutes at approximately 375° F.to bond the mixture to the fabric;

d) applying at least one rubber polymer to the cured fabric; andthereafter

e) vulcanizing the rubber to the fabric for a sufficient time and atsufficient pressure.

Additional features and advantages of the present invention are furtherdescribed, and will be apparent from the detailed description from thepresently preferred embodiments.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

In accordance with the present invention, a single adhesive formulationis disclosed that is capable of adhering a variety of rubber compoundsto woven fabric, in particular nylon, polyester and blends thereof. Theadhesive composition, comprises an aqueous mixture of: a) about 85 toabout 90 weight % of polychloroprene latex; b) about 2 to about 6 weight% of at least one prepolymer of resorcinol with formaldehyde; c) about 4to about 8 weight % of at least one blocked diisocyanate compound; andd) sufficient water to adjust the solids content of the mixture to about15 to about 40 weight %, wherein the percentage of solids add-on on thetreated fabric ranges between about 5 and about 20% based on theuntreated or griege fabric weight.

While the present adhesive composition contains between about 15 toabout 40 weight % solids, this percentage can vary depending on the "addon" required for a particular fabric substrate, in other words, theamount of solids needed to coat the fabric. Typically, approximately 12%add-on of mixed solids is applied to treated fabric based on the weightof the untreated fabric. Add-on is evaluated after the fabric has beendipped and dried. Insufficient add-on or too much add-on will cause pooradhesion of the rubber polymer to the fabric.

In the process of the present invention, pre-selected fabric is dippedinto or impregnated with the adhesive composition with sufficientpressure to allow the composition to penetrate the fabric. Any excess isremoved from the fabric. The treated fabric is then dried in acommercial oven at temperatures ranging between approximately 220° and275° F. for a sufficient period of time to dry the fabric. The fabric isthen cured at temperatures between about 300° and about 400° F. forabout 2 minutes. The fabric is then cooled. At this point, the fabric isnow ready to be bonded to a pre-selected rubber polymer byvulcanization.

For purposes of the present invention, although other polychloroprenelatexes may be used in the adhesive composition, the preferredpolychloroprene latex is Neoprene 571, a commercially available neoprenelatex from E.I. du Pont. The specifications for Neoprene 571 are shownbelow in Table I:

                  TABLE I                                                         ______________________________________                                        Neoprene 571                                                                  Neoprene                                                                        Latex Primary Co-Mo-  Emulsifier Chlorine                                     Type Monomer nomer Emulsifier Class Content %                               ______________________________________                                          571 Chloroprene Sulfur Principally Anionic 37.5                                  sodium salts                                                                  of resin acids                                                           ______________________________________                                                     Brook-                                                             pH  field                                                                     at Stan- Viscos-                                                              25°  dard ity at Spindle Speed  Applica-                               C. Solids 25° C. Number rpm Features tions                           ______________________________________                                          12.0 50 15[15] 1 6 High strength Adhesives                                      15[15] 1 30 cured films Coatings                                                 combined Dipped                                                               with low Goods                                                                permanent set                                                          ______________________________________                                    

As discussed in greater detail below, Formula 1524-12, a 24%resorcinol-formaldehyde neoprene, represents the adhesive compositionthat was used to carry out the present invention. To prepare Formula1524-12, the following steps were performed:

    ______________________________________                                        FORMULA 1524-12                                                                                                    % Dry                                      Wet Wt. Dry Wt. Wt.                                                         ______________________________________                                        1.   Weigh to black mix tank                                                     Neoprene 571 3150 1575.0 87.04                                               2. Weigh to black weigh tank.                                                  Mix for 5 min. Drain to                                                       black mix tank.                                                               Water 520                                                                     Ajack black 70 25.9 1.43                                                      Surfactant 40 10.0 0.55                                                      3. Weigh to black weigh tank.                                                  Drain to black mix tank.                                                      Age 1 hour before draining.                                                   Water 4000                                                                    SRF-1524 (pre-reacted 100 75.0 4.15                                           resorcinol/formaldehyde-                                                      Hooker Chemicals)                                                             Formaldehyde 50 18.5 1.02                                                     50% Caustic 10 5.0 0.28                                                      4. Weigh to black weigh tank and                                               drain to black mix tank.                                                      Grilbond IL-6 200 100 5.53                                                    Water 200                                                                    5. Stir for 30 minutes. Sample to lab.                                         TOTAL 8340 1869.4 100.0                                                    ______________________________________                                    

                  TABLE II                                                        ______________________________________                                        Q.C. ANALYSIS OF FORMULA 1524-12                                                Test        Method         Specification                                    ______________________________________                                        % Solids  HI-115         24.0% ± 1.5%                                        pH HI-102 10.0 ± 1.0                                                       Viscosity HI-103 Report                                                       Adhesion HI-0.5 Neoprene 20 lbs minimum                                        N1402001/14019011 @                                                           290° F. 30 min.                                                     ______________________________________                                    

It should be noted that Grilbond IL-6 represents the adhesion promoteror bonding agent that is used in the adhesive composition of the presentinvention. A blocked diisocyanate which functions by blocking moisture,Grilbond IL-6 is commercially available from EMS American Grilon Inc.,Sumter, S.C. Other blocked diisocyanates such as Desmodur TT may also beused.

To evaluate the adhesion of rubber polymers and rubber-like materials tofabrics, the following industry wide test method was used:

Test Method Specification

Procedure:

1. Cut two 4×8" samples from the treated fabric swatch to be tested. The8" cut is to be made in the warp direction.

2. Ply these samples by placing one piece of rubber (type and thicknessto be specified) 4×4" on each side and between the two fabric samples.Place the sample of fabric so that each face of the original samplecontacts the center separating rubber stock. Use tag cloth on each sideof ply to prevent sticking to the press platten.

3. Cure the ply in a press according to the desired specification fortemperature, pressure and time.* *If there are no specifications, cureat 290° F. for 30 min. at 125 psi.

4. Remove the cured ply from the press. Allow to cool and condition toroom temperature (at least 30 min.) Cut the sample to a width of exactlyone inch and a length of at least 6 inches. Make the cut so that itfollows a warp yarn.

5. Clamp the cut ply in a tensile tester set at a pull rate of 2 inchesper minute. Clamp the ply in the jaws of the tester so that the fabricwill be peeled from the separating rubber stock. Start the tester andallow it to peel for a distance of 3/4 before taking a reading. Withknife, cut the separating rubber stock so that it peels from one side offabric only. Record average reading for a distance of one inch.

6. Cut the separating rubber stock so that the rubber now peels from theother side of fabric. Record this average reading for a distance of oneinch.

The average reading for each sample of fabric was recorded. The averagewas based on two readings. The test specimens were examined and given aquantitative value.

The following results shown in Table III below were obtained followingadhesion tests on a variety of rubber polymers on nylon and polyesterfabrics using Formula 1524-12. The adhesion results are reported aspounds per lineal inch (pli).

                  TABLE III                                                       ______________________________________                                        FORMULA 1524-12                                                                      Neoprene Nitrile Hypalon                                                                              EPDM  Fluoroelastomer                          ______________________________________                                        Nylon  52       60      25     30    30                                         Polyester 35 30 35 28 32                                                    ______________________________________                                    

As shown in Table III, the single adhesive formula (1524-12) providedgood adhesion for a variety of rubber polymers to both nylon andpolyester fabric. All adhesion values are well-above the 20 lbs minimumthreshold that is commonly required by the rubber industry.

To demonstrate the advantages that the present adhesive composition hasover current RFL compositions, a number of comparative adhesion testswere conducted using typical RFL formulations and combinations thereof.These results are reported below:

    ______________________________________                                        COMPARATIVE RFL FORMULATION #1                                                ______________________________________                                        Neoprene 571      1860                                                          LVP 4668B 620                                                                 contains vinylpyridine                                                        Black KFO 400                                                                 Water 800                                                                     Water 2204                                                                    Formaldehyde-resin 160                                                        Formaldehyde 60                                                               Water 2041                                                                    Desmodur TT 170                                                               Surfactant 25                                                                  8340                                                                       ______________________________________                                    

Nylon fabric was impregnated or dipped with formulation #1, dried forabout 3 minutes at 265° F., and then cured for about 2 minutes at 400°F. Adhesion of various rubbers was tested and reported below in poundsper inch. With the use of a neoprene and vinylpyridine latex in theadhesive formulation, good adhesion was obtained only for nitrile, butnot for neoprene or EPDM.

Neoprene--7

EPDM--13

Nitrile--39

    ______________________________________                                        COMPARATIVE RFL FORMULATION #2                                                ______________________________________                                        Neoprene 571      1200                                                          LVP 4668B 1280                                                                contains vinylpyridine                                                        Black KFO 400                                                                 Water 800                                                                     Water 2204                                                                    Formaldehyde-resin 160                                                        Formaldehyde 60                                                               Water 1961                                                                    Desmodur TT 250                                                               Surfactant 25                                                                  8340                                                                       ______________________________________                                    

Nylon fabric was impregnated or dipped with formulation #2, dried forabout 3 minutes at 265° F., and then cured for about 2 minutes at 400°F. Adhesion of various rubbers was tested and reported below in poundsper inch. With the use of a neoprene and vinylpyridine latex inapproximately equal ratios, again as with formulation #1, good adhesionwas obtained for nitrile, but not for neoprene or EPDM.

Neoprene--7

EPDM--13

Nitrile--38

    ______________________________________                                        COMPARATIVE RFL FORMULATION #3                                                ______________________________________                                        LVP 4668B        3000                                                           Black KFO 400                                                                 Water 800                                                                     Water 2204                                                                    Formaldehyde-resin 221                                                        Formaldehyde 84                                                               Water 1436                                                                    Desmodur TT 170                                                               Surfactant 25                                                                  8340                                                                       ______________________________________                                    

Nylon fabric was impregnated or dipped with formulation #3, dried forabout 3 minutes at 265° F., and then cured for about 2 minutes at 400°F. Adhesion of various rubbers was tested and reported below in poundsper inch. With the use of a vinylpyridine latex, good adhesion wasobtained only for nitrile, but not for neoprene or EPDM.

Neoprene--5

EPDM--12

Nitrile--44

    ______________________________________                                        COMPARATIVE RFL FORMULATION #4                                                ______________________________________                                        LVP 4668B        1500                                                           Hycar 1572 - 1500                                                             a nitrile latex                                                               Black KFO 400                                                                 Water 800                                                                     Water 2204                                                                    Formaldehyde-resin 221                                                        Formaldehyde 84                                                               Water 1436                                                                    Desmodur TT 170                                                               Surfactant 25                                                                  8340                                                                       ______________________________________                                    

Nylon fabric was impregnated or dipped with formulation #4, dried forabout 3 minutes at 265° F., and then cured for about 2 minutes at 400°F. Adhesion of various rubbers was tested and reported below in poundsper inch. With the use of a vinylpyridine and nitrile latex inapproximately equal ratios in the adhesive formulation, good adhesionwas obtained only for nitrile, but not for neoprene or EPDM.

Neoprene--6

EPDM--8

Nitrile--44

    ______________________________________                                        COMPARATIVE RFL FORMULATION #5                                                ______________________________________                                        LVP 4668B        750                                                            Hycar 1572 2250                                                               Black KFO 400                                                                 Water 800                                                                     Water 2204                                                                    Formaldehyde-resin 221                                                        Formaldehyde 84                                                               Water 1436                                                                    Desmodur TT 170                                                               Surfactant 25                                                                  8340                                                                       ______________________________________                                    

Nylon fabric was impregnated or dipped with formulation #5, dried forabout 3 minutes at 265° F., and then cured for about 2 minutes at 400°F. Adhesion of various rubbers was tested and reported below in poundsper inch. With the use of a vinylpyridine and a larger amount of nitrilelatex in contrast to formulation #4, good adhesion was obtained only fornitrile, but not for neoprene or EPDM.

Neoprene--9

EPDM--8

Nitrile--38

    ______________________________________                                        COMPARATIVE RFL FORMULATION #6                                                ______________________________________                                        Hycar 1572       1500                                                           Neoprene 571 1500                                                             Black KFO 400                                                                 Water 800                                                                     Water 2204                                                                    Formaldehyde-resin 221                                                        Formaldehyde 84                                                               Water 1436                                                                    Desmodur TT 170                                                               Surfactant 25                                                                  8340                                                                       ______________________________________                                    

Nylon fabric was impregnated or dipped with formulation #6, dried forabout 3 minutes at 265° F., and then cured for about 2 minutes at 400°F. Adhesion of various rubbers was tested and reported below in poundsper inch. With the use of a nitrile and neoprene latex, good adhesionwas obtained only for nitrile, but not for neoprene or EPDM.

Neoprene--17

EPDM--9

Nitrile--40

    ______________________________________                                        COMPARATIVE RFL FORMULATION #7                                                ______________________________________                                               Hycar 1572                                                                             3000                                                            Black KFO 400                                                                 Water 800                                                                     Water 2200                                                                    SRF 1524 150                                                                  Formaldehyde 84                                                               Ammonia 30                                                                    Water 1700                                                                     8364                                                                       ______________________________________                                    

Nylon fabric was impregnated or dipped with formulation #7 with anadjusted pH of 9.5, dried for about 3 minutes at 265° F., and then curedfor about 2 minutes at 400° F. Adhesion of various rubbers was testedand reported below in pounds per inch. With the use of a nitrile latexonly, good adhesion was obtained for nitrile and neoprene, but not forEPDM and styrene butadiene rubber.

Nitrile--47/35

EPDM--3

Neoprene--29

Styrene butadiene

    ______________________________________                                        COMPARATIVE RFL FORMULATION #8                                                ______________________________________                                        Formula 2002 -     2670                                                         a styrene butadiene latex                                                     Formula 4668 - 3330                                                           contains vinylpyridine                                                        Water 663                                                                     Surfactant 400                                                                Black KFO 300                                                                 Water 1000                                                                    SRf 1524 203                                                                  Formaldehyde 124                                                              Caustic 10                                                                  ______________________________________                                    

The formulation contained 35% solids and the latex to resin ratio was13.7 parts to 1 part. Nylon fabric was impregnated or dipped withformulation #8, dried for about 3 minutes at 265° F., and then cured forabout 4 minutes at 350° F. Adhesion of various rubbers was tested andreported below in pounds per inch. With the use of a styrene butadieneand vinylpyridine latex, good adhesion was obtained for the styrenebutadiene rubber and EPDM, but not for neoprene or nitrile.

Styrene butadiene rubber--85

Neoprene--3

EPDM--30

Nitrile--3

    ______________________________________                                        COMPARATIVE RFL FORMULATION #9                                                ______________________________________                                        Formula 4668      5200                                                          contains vinylpyridine                                                        1509S-5 40                                                                    surfactant                                                                    Water 40                                                                      Water 2280                                                                    Caustic 10                                                                    SRF 1524 165                                                                  Formaldehyde 105                                                              Water 250                                                                     Grilbond-IL6 250                                                            ______________________________________                                    

The formulation contained 35% solids and the latex to resin ratio was13.7 parts to 1 part. Nylon fabric was impregnated or dipped withformulation #9, dried for about 3 minutes at 265° F., and then cured forabout 4 minutes at 350° F. Adhesion of various rubbers was tested andreported below in pounds per inch. With the use of a vinylpyridinelatex, good adhesion was obtained for styrene butadiene rubber and EPDM,but not for neoprene or nitrile.

Styrene butadiene rubber--90

Neoprene--6

EPDM--23

Nitrile--8

    ______________________________________                                        COMPARATIVE RFL FORMULATION #10                                               ______________________________________                                        Neoprene Latex 571                                                                              3000                                                          Formula 4668 1540                                                             contains vinylpyridine                                                        Water 3289                                                                    SRF 1524 346                                                                  Formaldehyde 165                                                              No adhesion promoter                                                        ______________________________________                                    

The formulation contained 35% solids and the latex to resin ratio was13.7 parts to 1 part. Nylon fabric was impregnated or dipped withformulation #10, dried for about 3 minutes at 265° F., and then curedfor about 4 minutes at 350° F. Adhesion of various rubbers was testedand reported below in pounds per inch. With the use of a neoprene andvinylpyridine latex, good adhesion was obtained for the fluoroelastomerand EPDM, but not for neoprene or nitrile.

Neoprene--12

EPDM--34

Nitrile--12

Fluoroelastomer--35

As demonstrated by comparative RFL formulations #1 through #10, nosingle formulation provided good adhesion for all of the rubber polymerstested. Instead, adhesion of the rubbers to the fabric varied dependingon which rubber polymer(s) was contained in the adhesive formulation. Bycontrast, the adhesive formulation of the present invention providedhigh adhesion for a number of rubber polymers to both nylon andpolyester. It is expected that similar results may be achieved usingblends of the nylon and polyester.

It should be understood that various changes and modifications to thepresently preferred embodiments described herein will be apparent tothose skilled in the art. Such changes and modifications can be madewithout departing from the scope of the present invention withoutdiminishing its attendant advantages. It is therefore intended that suchchanges and modifications be covered by the appended claims.

We claim:
 1. An adhesive composition for bonding a variety of rubberpolymers to fabric, comprising an aqueous mixture of:a) apolychloroprene latex; b) at least one prepolymer of resorcinol withformaldehyde; c) at least one blocked diisocyanate compound; and d)sufficient water to adjust the solids content of the mixture to about 15to about 40% by weight; wherein the composition is capable of bindingmore than one class of rubber polymer and the percentage of solidsadd-on on fabric treated with the composition ranges between about 5 andabout 20% based on the weight of the untreated fabric.
 2. The adhesivecomposition according to claim 1, wherein the polychloroprene latexcomprises a copolymer of chloroprene with sulfur.
 3. The adhesivecomposition according to claim 1, wherein the class of rubber polymer isselected from the group consisting of polychloroprene, nitrile, naturalrubber, hypalon, ethylene-propylene (EPDM) and fluoroelastomer.
 4. Theadhesive composition according to claim 1, wherein the blockeddiisocyanate compound is caprolactam blockedmethylene-bis-(4-phenylisocyanate).
 5. The adhesive compositionaccording to claim 1, wherein the polychloroprene latex is in an amountof between 85 and about 90% by weight in the composition.
 6. Theadhesive composition according to claim 1, wherein additionalformaldehyde is added to the mixture to enhance the chemical reaction ofthe mixture.
 7. The adhesive composition according to claim 1, whereinthe composition further includes a non-ionic surfactant in an amount ofabout 0.5 weight %.
 8. The adhesive composition according to claim 1,wherein the composition further includes caustic soda in an amount ofabout 0.2 to about 0.4 weight %.
 9. The adhesive composition accordingto claim 1, wherein the treated fabric is woven fabric.
 10. The adhesivecomposition according to claim 9, wherein the woven fabric includesnylon, polyester and blends thereof.
 11. An adhesive composition forreinforcing a variety of rubber polymers to fabric, comprising anaqueous mixture of:a) about 85 to about 90 weight % polychloroprenelatex; b) about 2 to about 6 weight % of at least one prepolymer ofresorcinol with formaldehyde; c) about 4 to about 8% by weight of atleast one blocked diisocyanate compound; and d) sufficient water toadjust the solids content of the mixture to about 15 to about 40% byweight; wherein the composition is capable of binding more than oneclass of rubber polymer and the percentage of solids add-on on fabrictreated with the composition ranges between about 5 and about 20% basedon the weight of the untreated fabric.
 12. The adhesive compositionaccording to claim 11, wherein the class of rubber polymer is selectedfrom the group consisting of polychloroprene, nitrile, natural rubber,hypalon, ethylene-propylene (EPDM) and fluoroelastomer.
 13. The adhesivecomposition according to claim 11, wherein the blocked diisocyanatecompound is caprolactam blocked methylene-bis-(4-phenylisocyanate). 14.The adhesive composition according to claim 11, wherein additionalformaldehyde is added to the mixture to enhance the chemical reaction ofthe mixture.
 15. The adhesive composition according to claim 11, whereinthe composition further includes a non-ionic surfactant in an amount ofabout 0.5 weight %.
 16. The adhesive composition according to claim 11,wherein the treated fabric is woven fabric.
 17. The adhesive compositionaccording to claim 16, wherein the woven fabric includes nylon,polyester and blends thereof.